Fluorinated organic molecules are increasingly used in life science industries. The presence of a fluorine substituent can have positive effects on the biological properties of compounds. Thus, synthetic techniques for fluorinating compounds are a significant area of interest.
The selective fluorination of aryl and heteroaryl substrates is a challenging synthetic problem. As an example, mono- and di-chloro substituted picolinate esters are difficult to fluorinate and require more expensive metal fluorides (e.g., cesium fluoride (CsF)) to generate acceptable yields. Under Halex (halogen exchange) conditions, which use potassium fluoride, the chemical yields are often quite low (<20%). Also, Halex conditions usually require a phase transfer catalyst, a high boiling solvent, and high temperatures. Such conditions can preclude the use of Halex conditions in many systems. What is needed are new methods for fluorinating compounds, especially a wide variety of fluorinated compounds, and the methods and compounds disclosed herein address these and other needs.